AD7876 AD [Analog Devices], AD7876 Datasheet
AD7876
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AD7876 Summary of contents
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... All parts operate from 5 V power supplies. The AD7870 and AD7876 accept input signal ranges and 10 V, respec- tively, while the AD7875 accepts a unipolar input range. The parts can convert full power signals kHz. ...
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... AD7870/AD7875/AD7876–SPECIFICATIONS A6ND = DGND = 2.5 MHz external, unless otherwise stated. All Specifications T CLK Parameter 2 DYNAMIC PERFORMANCE 3 Signal to Noise Ratio (SNR MIN MAX Total Harmonic Distortion (THD) Peak Harmonic or Spurious Noise Intermodulation Distortion (IMD) Second Order Terms Third Order Terms ...
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... POWER REQUIREMENTS NOTES 1 Temperature ranges are as follows: AD7875 Versions + Versions, – + Version, – +125 C. AD7876 Versions, – + Version, – +125 C. 2 Includes internal reference error and is calculated after unipolar offset error (AD7875) or bipolar zero error (AD7876) has been adjusted out. ...
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... ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD7870/AD7875/AD7876 feature proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality ...
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... Voltage SNR IN Range (V) (dBs min min min min min min min AD7876 ORDERING GUIDE Integral V Voltage Nonlinearity IN Range (V) (LSB max 10 1/2 max 10 1 max 10 1/2 max 10 1 max 10 ...
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... REF OUT Voltage Reference Output. The internal 3 V reference is provided at this pin. The external load capability is 500 Analog Input. The analog input range for the AD7870 for the AD7876 and for the AD7875 Negative Supply, –5 V ...
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... ADC’s internal operation. Figure 3. Reference Circuit The reference output voltage For applications using the AD7875 or AD7876 reference may be required. Figure 4 shows how to scale the 3 V REF OUT voltage to pro- vide either external reference. ...
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... R2 until the ADC output code flickers between 1000 0000 0000 and 1000 0000 0001. OFFSET AND FULL-SCALE ADJUSTMENT—AD7876 The offset and full-scale adjustment for the AD7876 is similar to that just outlined for the AD7870. The trim procedure, for those applications that do require adjustment follows: apply a voltage of – ...
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... BUSY/INT. DATA OUTPUT FORMATS In addition to the two operating modes, the AD7870/AD7875/ AD7876 also offers a choice of three data output formats, one serial and two parallel. The parallel data formats are a single, 12-bit parallel word for 16-bit data buses and a two-byte format for 8-bit data buses ...
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... AD7870/AD7875/AD7876 Figure 10. Mode 1 Timing Diagram, Byte or Serial Read The Mode 1 timing diagram for byte and serial data is shown in Figure 10. INT goes low at the end of conversion and is reset high by the first falling edge of CS and RD. This first read at the end of conversion can either access the low byte or high byte of data depending on the status of HBEN (Figure 10 shows low byte only for example) ...
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... The AD7870 and AD7875 are specified and 100% tested for dynamic performance specifications as well as traditional dc specifications such as integral and differential nonlinearity. Al- though the AD7876 is not production tested for ac parameters, its dynamic performance is similar to the AD7870 and AD7875. The ac specifications are required for signal processing applica- tions such as speech recognition, spectrum analysis and high speed modems ...
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... AD7870/AD7875/AD7876 Figure 14 shows a typical plot of effective number of bits versus frequency for an AD7870KN/AD7875KN with a sampling fre- quency of 100 kHz. The effective number of bits typically falls between 11.7 and 11.85 corresponding to SNR figures of 72.2 and 73.1 dB. Figure 14. Effective Number of Bits vs. Frequency Total Harmonic Distortion (THD) THD is the ratio of the rms sum of harmonics to the rms value of the fundamental ...
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... MICROPROCESSOR INTERFACE The AD7870/AD7875/AD7876 has a wide variety of interfacing options. It offers two operating modes and three data-output for- mats. Fast data access times allow direct interfacing to most mi- croprocessors including the DSP processors. Parallel Read Interfacing Figures show interfaces to the ADSP-2100, TMS32010 and the TMS32020 DSP processors ...
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... Figure 23. TMS32020 Serial Interface ADSP-2101/ADSP-2102 Serial Interface Figure 24 shows a serial interface between the AD7870/AD7875/ AD7876 and the ADSP-2101/ADSP-2102. The ADC is config- ured for continuous clock operation. Data is clocked into the serial port register of the ADSP-2101/ADSP-2102 during con- version. As with the previous interfaces, when a 16-bit data ...
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... STAND-ALONE OPERATION The AD7870/AD7875/AD7876 can be used in its Mode 2, par- allel interface mode for stand-alone operation. In this case, con- version is initiated with a pulse to the ADC CS input. This pulse must be longer than the conversion time of the ADC. The BUSY output is used to drive the RD input. Data is latched from the ADC DB0– ...
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... SKT6). The –5 V supply required by the ADC is generated from a voltage regulator on the V– power supply input (IC3 in Figure 27). COMPONENT LIST IC1 AD711 Op Amp IC2 AD7870/AD7875/AD7876 Analog-to- Digital Converter IC3 MC79L05 –5 V Regulator IC4 74HC00 Quad NAND Gate IC5 ...
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... Figure 28. Data Acquisition Circuit Using the AD7870/AD7875/AD7876 REV. B Figure 29. PCB Silkscreen for Figure 28 –17– AD7870/AD7875/AD7876 2 ...
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... AD7870/AD7875/AD7876 Figure 30. PCB Component Side Layout for Figure 28 Figure 31. PCB Solder Side Layout for Figure 28 –18– REV. B ...
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... Plastic DIP (N-24) 24-Pin Cerdip (Q-24) REV. B OUTLINE DIMENSIONS Dimensions shown in inches and (mm). –19– AD7870/AD7875/AD7876 28-Pin PLCC (P-28A) 24-Pin SOIC (R-24) 2 ...
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